Field of the Invention
The present invention relates to water softener or detergent compositions and co-granulates comprising an effervescent agent and pectin, unit portions comprising said co-granulates or compositions, use of said compositions or co-granulates in water-soluble and/or water-dispersible water softening, cleaning or detergent formulations and to the use of pectin to stabilize effervescent tablets.
Description of the Related Art
Tabletted detergent compositions or detergent compositions in unit portions have become increasingly popular as they are easy to handle and avoid over- or under-dosing and spillage of detergent. However, one major disadvantage is that tablets and other unit portions are often compressed or compacted and therefore do not always disintegrate, dispense or dissolve satisfactory in the washing water. This results in an inefficient delivery of the active agents to the wash, in lumping of the product in the washing machine or dish washer and in deposition of product onto fabric or tableware. One solution for this problem presented in the prior art is the incorporation of effervescent agents into the tablet, which form gas upon contact with water and thereby contribute to improved disintegration, dissolution and dispersion of the tabletted or portioned composition.
The use of effervescent agents advantageously allows the very rapid disintegration, dispensing and dissolution of the solid dosage forms, such as tablets and other unit portions. In addition, after dissolving, minimal to none manipulation is needed in order to ensure appropriate mixing of the constituents including the active agents of the solid dosage compositions, in particular tablets, such that uniform applications can be assured with the reconstituted aqueous solutions, including water softening, cleaning and detergent solutions.
However, tablets/unit portions comprising effervescent agents based on an acid-base system are difficult to store, especially in a humid or moist environment as too high air humidity can already start the effervescent reaction which results in physical instability of the tablet or unit portion.
Thus, tablets/unit portions comprising effervescent agents are often particularly difficult to store over a period of several weeks up to months unless ingredients with decreased moisture content, i.e. with a moisture content ranging from 0 to 3 wt.-% of the dry compound are utilized for tablet production. Tablets made of compounds with normal moisture content, i.e. ranging from 0.5 to 15 wt.-% of the dry compound show often limited stability during storage, i.e. exhibit swelling and crumbling during a few weeks of storage.
To avoid water contact and allow prolonged storage, tabletted effervescent compositions are often packaged in water proof paper, water insoluble films or foil, as recommended for example in DE 19745964 A1.
Further attempts to increase stability of effervescent detergent tablets include coating of the tablets. To increase stability, particularly abrasion stability of effervescent detergent tablets, WO 98/24873 A1 proposes to apply a thin but hard coating that is readily dissolvable when the tablet is in the washing machine.